At least since the publication of the important article “It’s the Prices, Stupid,”1 it has been known that the substantial gap in health care spending between the United States and other developed countries is largely because of differences in prices, not use of health care services. Moreover, even at higher price (and spending) levels, most health care outcomes in the United States are not superior to those of peer nations. These facts have motivated calls by some to regulate health care prices in the United States.